Authorities said crews investigating the source of the spill said it was small. Fire officials estimated the substance was spilling at an estimated rate of about five gallons per hour, said Ventura County Fire Department spokesman Steve Swindle.

A hazardous-materials response team was requested, and the Coast Guard and California Department of Fish and Game were on scene, officials said. The California Highway Patrol was requested in case the spill went into the roadside, officials said. The CHP said about 3:45 p.m. it found no traffic hazard.

About 5 p.m., the Fire Department turned over the investigation to the Ventura County Environmental Health Division, officials said.

Environmental Health is investigating the spill and whether the water was affected, officials said.